Spinal fusion surgery is a procedure to correct problems with vertebrae by basically welding them together and allowing them to heal into one solid bone. This procedure may relieve symptoms of back problems such as fracture, scoliosis, spinal stenosis, spondylolisthesis, and degenerative disk disease. The idea is to prevent pain by preventing movement. Some form of bone material must be utilized in order to promote the fusion and healing. This procedure is called a bone graft and involves placing pieces of bone into the area between the vertebrae and sometimes additional pieces elsewhere for support. Previously, the only way to do this was by making an additional incision to harvest a bone graft from the hip (called an autograft). This meant a longer procedure time and possibly a more complicated healing process. Now, there are alternatives to bone grafts such as use of a cadaver bone (called an allograft) or the use of an artificial bone graft material.
Nine years ago the FDA approved Medtronic's Infuse Bone Graft for one particular type of spinal fusion surgery. It was one of the alternatives to harvesting a bone graft from the hip. Eventually it was also used, albeit off-label, with other types of spinal surgeries, such as cervical spine surgeries. Doctors are free to prescribe drugs beyond their official uses (though insurance companies, such as Medicare and Medicaid, may choose to reimburse only if there is a representation that the product will be used for its intended use). Some researchers estimate off-label uses at 85% of total Infuse use. What followed the extraneous uses were numerous reports of side effects and complications such as death, cancer, sterility, infections, bone dissolution, worsened back and leg pain, ectopic bone (bone outside of the target area), and swelling of the neck and throat area (leading to suffocation).
As a result, in the Fall of 2008, the Justice Department began to investigate. It turns out that some of the adverse side effects reported above had been found in 10-50% of patients who were given Infuse or its sister product during clinical trials funded by Medtronic over a decade long study. But not all of the findings (namely the risk of sterility) were reported in the research papers by Medtronic's surgeons or written on the product label. In a number of their papers regarding Infuse, they also failed to disclose their financial ties to Medtronic. Coincidentally, 15 of Medtronic's surgeons had been paid upwards of $62 million over the last 10 years for "unrelated" work.
The probe also revealed that the physicians who reviewed a sister product of Infuse, Amplify, completely omitted the 90-95% probability of a link between the product and cancer, which had been discussed in 15 of the 68 pages of the FDA's summary of the product. Furthermore, 3 of the surgeons who were involved in the trial of that product were paid at least $10 million by Medtronic since 2001.
Medtronic was directed not to destroy its reports. Presently, the Senate Finance Committee is investigating whether doctors with financial ties to Medtronic were aware of potentially serious complications with products yet failed to reveal those problems in published journal articles.
By Kathleen Beatty